Editor’s note: The writer is addressing the question, “Are eco-friendly renewables key to a non-carbon energy future?”

GREEN BAY, Wis. — The U.S. relies heavily on fossil fuels to meet its energy needs, and a large portion of that use is for producing electricity.

Coal-fired power plants provide 30 percent of electricity generation by the country’s utilities, with natural gas contributing 34 percent and nuclear power about 20 percent.

In contrast, renewables provide only 10 percent of overall U.S. energy use and 15 percent of the nation’s electricity, split about equally between hydropower and wind.

Critics say this is far too low for renewables to be a major contributor to electricity generation in the foreseeable future. But the critics’ conclusion is wrongheaded for three reasons.

One is that burning fossil fuel emits greenhouse gases linked to climate change and contributes to poor air quality. There is a growing consensus that the world needs to rely far less on them going forward.

The second reason is that while nuclear power does not contribute directly to greenhouse gas emissions, most analysts think it unlikely that it will be a bigger force in the future. Nuclear power is too expensive in its present form, the public doesn’t trust it and it remains hobbled by the unresolved questions of how to dispose of radioactive waste effectively.

The third reason that negative views of renewable energy’s potential are off the mark is simply that much has changed in the last few years in the technologies and their cost.

A good indicator is that more than half of electricity generation capacity added to the U.S. grid in 2016 came from renewables. Globally, two-thirds of new generating capacity came from renewable sources.

The reasons are falling prices and improved efficiency.

As noted energy expert Hal Harvey, the CEO of San Francisco’s Energy Innovation said in 2016, “a clean future now costs less than a dirty one.”

Thus, moving toward renewable energy makes a lot of economic, environmental and public health sense.

Still, some argue that renewables will need to prove themselves further in the marketplace and that we need better ways to store the electricity for periods when wind is scarce and the sun isn’t shining.

Neither obstacle is as formidable as we once thought. Battery storage technologies are improving rapidly and costs are falling, much as we saw with the advent of flat-screen televisions.

The earliest impact will be in those areas of the nation that already are making the leap to renewables. States in the top 10 for electricity derived from renewables are a diverse lot, suggesting that partisanship and ideology are not important factors.

Similarly, cities that already rely on renewables for 100 percent of their electricity include liberal Burlington, Vermont, but also conservative Georgetown in oil-rich Texas.

It is a widely shared sentiment today, with many other cities, large and small, pledging to reach the same goal, including San Francisco, Orlando, St. Louis and Portland.

Similarly, most states have set impressive goals for renewable energy, with a few aiming very high. California and New York aspire to having 50 percent of their energy generated from renewables by 2030, while Hawaii expects to hit 100 percent by 2045.

The benefits in improved air quality, public health and reduced greenhouse gas emissions are substantial, and recent studies tell us they will grow over time while also increasing employment and strengthening the economy.

— Michael Kraft is professor emeritus of political science and public and environmental affairs at the University of Wisconsin-Green Bay.